3. A mercury water manometer indicates a gauge difference of 400 mm. The difference in pressure, measured in metres of water, is
A. 5.44
B. 0.4
C. 0.8
D. 1088
3. A mercury water manometer indicates a gauge difference of 400 mm. The difference in pressure, measured in metres of water, is
A. 5.44
B. 0.4
C. 0.8
D. 1088